6-K

FORM 6-K

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE

SECURITIES EXCHANGE ACT OF 1934

Dated July 21, 2009

Commission File Number 1-14878

GERDAU S.A.

(Exact Name as Specified in its Charter)

N/A

(Translation of Registrant’s Name)

Av. Farrapos 1811

Porto Alegre, Rio Grande do Sul - Brazil CEP 90220-005

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F   x Form 40-F   o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): o

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes   o No   x

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):  Not applicable.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused the Report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date:  July 21, 2009

GERDAU S.A.
By:	/s/Osvaldo Burgos Schirmer
Name:  Osvaldo Burgos Schirmer
Title:   Chief Financial Officer

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EXHIBIT INDEX

Exhibit	Description of Exhibit
99.1	Notice to the Market, July 21, 2009

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EX-99.1

Exhibit 99.1

NOTICE TO THE MARKET

GERDAU S.A. (Bovespa: GGBR; NYSE: GGB; Latibex: XGGB) hereby announces that the Form 20-F relating to the fiscal year ended December 31, 2008 was filed with the U.S. Securities and Exchange Commission (SEC) and the Securities and Exchange Commission of Brazil (CVM) and is available at the Company’s Investor Relations Website (www.gerdau.com/investidores).

Shareholders may request a free copy of the Form 20-F from the IR team by sending an email to inform@gerdau.com.br or by calling +55 51 3323-2703.

The Company also informs that the contents of the Form 20-F comply with the International Financial Reporting Standards (IFRS) established by the International Accounting Standards Board (IASB), in yet another effort by the Company to maintain its excellence in corporate governance standards.

Rio de Janeiro, July 21, 2009

Osvaldo Burgos Schirmer

Executive Vice-President and

Investor Relations Officer